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Thursday, April 15, 2010

Are plover protections protecting plovers?

Are plover protections protecting the plovers? Once you take a look at the data, it becomes obvious that they are not. There are 19 birds left in Humboldt county. The steady decline since intensive monitoring began 10 years ago might have more to do with how we are trying to help them than we may be comfortable in admitting.

Beach grass eradication seems to have no consistent benefit to plover populations, which have been concerns cited by HSU professor Mark Colwell as well as noted in the Fish and Wildlife Service's plover recovery plan. It is hard to say whether benefits to the plover will be a legitimate aspect of restoration grant requests any more. There is already quite a lot of what is considered ideal habitat, yet plovers don't seem to take advantage of it. Initially, the restored areas have too little cover for protection, in my observations, and in ensuing years perhaps too much dense vegetation for nesting. This is also a stated concern in the recovery plan.

During a discussion regarding predator control measures with the Fish and Wildlife Service, we found there would be several difficulties with initiating an effective program. They were not willing to discuss measures being considered for future implementation, however. Killing crows and ravens will obviously not be very popular with the public. And, as they say, “Kill one crow and a hundred will show up at its funeral.” The removal of one of the beach's most important janitors ould likely lead to further problems, anyway. So far, predator control consists of crow-proof garbage cans and educating the public. There appears to be as many, if not more, crows and ravens out there lately.

To say that the symbolic fencing has helped fledge rates is actually a bit misleading. The first two years out of the last five that the fencing has been used, there were more fledged birds within the fencing compared to outside of it. Unfortunately, the last two years have produced no fledged plovers anywhere on Clam Beach. In the middle year, there was one fledged within and one outside. However, the fencing was erected around an area that already had the higher fledge rates in previous years.

There have been a few unfortunate incidents where human activity has caused eggs to be crushed. However, if we are going to be honest here, the likelihood that any of them would have survived corvid predation is pretty slim. Aside from a few nests being victims of wind and weather, just about all eggs and chicks end up in the gullet of a raven.

All is not without hope, however. What could be a sensible alternative to this ongoing downward spiral is to simply gather these eggs for incubation for a period of, say, three years, to give the population a much-needed boost. The goal is to have a self-sustaining population, of course, but this would also likely discourage nesting in these poor productive areas. Last year this did happen with a pair that had several unsuccessful nests on Clam Beach before heading to Big Lagoon, where they hatched and fledged all three chicks. Raising them to fledgling age and releasing them in more suitable habitats could at least give them a chance.

Another concern that should get some additional attention is banding. If we were to band only half of these “hatchery” birds, that could help us determine if ravens are keying in on the brightly colored bands that helps researchers identify individuals. And by being able to band them at a more advanced age, we would reduce the incidents of injury or death during the banding process. This concern was also noted in the recovery plan. Older chicks are much less vulnerable to predation, also.

This may not be the end-all to the recovery of the snowy plover, but if we don't change our approach and create reasonable expectations, we are not going to be sharing the beach with them any more. Either there will be no snowy plovers left, or increasing restrictions may end up allowing us to visit our beaches only in our memories.